BACKGROUND Lichen planus disease is a chronic inflammatory disorder of mucosal and cutaneous tissues, and its etiology and pathogenesis are unclear. Cytokines have a significant role in the beginning, the maintenance of inflammatory and intercellular crosstalk. OBJECTIVE We assessed serum levels of neutrophil activation marker (calprotectin) in patients with cutaneous lichen planus with different subtypes and made a comparison with healthy individuals. METHODS Peripheral blood samples of 30 cases with lichen planus were compared with 30 healthy individuals. Serum samples were prepared from LP patients, using a commercial ELISA kit, and calprotectin level was measured in each serum sample. RESULTS The serum level of calprotectin was significantly raised in LP cases compared with control (141.34 ± 17.47 ng/ml versus 40.03 ± 1.54 ng/ml respectively; p < 0.001). No correlation was recorded among of serum of calprotectin and patients' ages, sex, disease period, and the existence or strength of pruritus. But a strong positive correlation was present between the coexistence of oral lesions and the number of locations. CONCLUSIONS Calprotectin can be used as a marker of Lichen planus severity and progression. Calprotectin may play a role in the pathogenesis of LP.